At the level, judges are nominated by the president and confirmed by the senate according to their advise-and-consent responsibility as stated in the constitution.

Federal level
 Federal judges are nominated by the president and approved  by the senate. these judges include district court judges, court of appeal judges and the supreme court judges.

Bob: coke is baby pandas.jim: what? how do you figure that coke is baby pandas? bob: because this book says so.jim: how do we know the book is correct? bob: because it says that coke is baby pandas.jim: how does that prove the book's accuracy? bob: because it's statement involving coke and baby pandas is correct, therefore it is accurate.jim: how do we know that it's correct? bob: because we have concluded that the book is accurate, and therefore the statement is correct.therefore, coke is baby pandas.